Revealing Alteration in the Hepatic Glucose Metabolism of Genetically Improved Carp, Jayanti Rohu <i>Labeo rohita</i> Fed a High Carbohydrate Diet Using Transcriptome Sequencing

• Main Authors: Kiran D. Rasal, Mir Asif Iquebal, Sangita Dixit, Manohar Vasam, Mustafa Raza, Lakshman Sahoo, Sarika Jaiswal, Samiran Nandi, Kanta Das Mahapatra, Avinash Rasal, Uday Kumar Udit, Prem Kumar Meher, Khuntia Murmu, UB Angadi, Anil Rai, Dinesh Kumar, Jitendra Kumar Sundaray
• Format: Article
• Language: English
• Published: MDPI AG 2020-10-01
• Series: International Journal of Molecular Sciences
• Subjects: <i>Labeo rohita</i>; transcriptome; gene ontology; KEGG; insulin signaling pathway
• Online Access: https://www.mdpi.com/1422-0067/21/21/8180
• ISSN: 1661-6596; 1422-0067

Although feed cost is the greatest concern in aquaculture, the inclusion of carbohydrates in the fish diet, and their assimilation, are still not well understood in aquaculture species. We identified molecular events that occur due to the inclusion of high carbohydrate levels in the diets of genetically improved ‘Jayanti rohu’ <i>Labeo rohita</i>. To reveal transcriptional changes in the liver of rohu, a feeding experiment was conducted with three doses of gelatinized starch (20% (control), 40%, and 60%). Transcriptome sequencing revealed totals of 15,232 (4464 up- and 4343 down-regulated) and 15,360 (4478 up- and 4171 down-regulated) differentially expressed genes. Up-regulated transcripts associated with glucose metabolisms, such as <i>hexokinase, PHK, glycogen synthase</i> and <i>PGK</i>, were found in fish fed diets with high starch levels. Interestingly, a de novo lipogenesis mechanism was found to be enriched in the livers of treated fish due to up-regulated transcripts such as <i>FAS</i>, <i>ACCα</i>, and <i>PPARγ</i>. The insulin signaling pathways with enriched PPAR and mTOR were identified by Kyoto Encyclopedia of Genes and Genome (KEGG) as a result of high carbohydrates. This work revealed for the first time the atypical regulation transcripts associated with glucose metabolism and lipogenesis in the livers of Jayanti rohu due to the inclusion of high carbohydrate levels in the diet. This study also encourages the exploration of early nutritional programming for enhancing glucose efficiency in carp species, for sustainable and cost-effective aquaculture production.